Rising food demand has many causes, from raised climate instability to demographic growth, to urbanization (loss of subsistence production), to higher emerging market (particularly Indian and Chinese) living standards, to speculation and hoarding, and so on.

FORBES: High Commodity Food-Price Decade Challenges All Global Managers

They warn of what 11 retired generals and admirals wrote about in 2007 - climate change becoming a 'force multiplier for instability in some of the most volatile regions of the world'.

BBC: Climate: 2C or not 2C?

Today, no country is in the old sense far away when the consequences of regional instability and terrorism - and then also climate change, poverty, mass population movements and even organised crime - reverberate quickly round the globe.

BBC: In full: Brown security statement

His book highlights six mega-trends causing instability: unfavourable demographics, resource scarcity, climate change, geopolitical rebalancing, indebtedness and fiscal issues, and rising inequality.

FORBES: Managing Disequilibrium

Global climate change is likely to trigger humanitarian disasters and political instability that will have a major impact on U.S. national security, a top intelligence official told Congress on Wednesday.

NPR: Linking Climate Change, National Security

Timothy Lenton, a climate scientist at the University of Exeter, argues that such pollution could trigger wider instability in the monsoon.

ECONOMIST: India��s climate: Monsoon, or later | The